1. Field of the Invention
In general, this invention relates to a soil-sterilizing apparatus which may be used to prepare soil for small plant growth or seed germination.
2. Description of the Prior Art
One known method for sterilizing soil employs steam to destroy organisms, insects and fungii which are injurious to plant growth; however, this method is not widely used because it requires expensive steam generating equipment. Moreover, the costs and delays associated with steam generation makes this system impractical for commercial purposes because it requires large amounts of fuel and inordinately high temperatures in order to produce the pressures needed for bringing the steam into intimate contact with the soil over extended periods. Accordingly, steam sterilization is usually employed only where the area to be treated is relatively small, a limitation which makes it unsuitable for use in large scale projects as, for example, in commercial landscaping projects of any magnitude.
Another known method for sterilizing soils involves the application of liquid-chemicals such as sodium methyl dithiocarbonate (i.e., VAPAM, a product of Stauffer Chemical Company, New York, N.Y.) In practice, this chemical must be applied to damp or wet soil which is then covered with an air impervious sheet for approximately two weeks. This procedure is so laborious and time consuming as to be impractical for use on anything other than small soil areas.
It is an object of this invention to provide an apparatus, which, when used with known fumigants, provides an inexpensive and practical means for converting contaminated soil into sterilized form in commercial quantities.